1. Technical Field
The invention relates to an improved process for the preparation of substituted anisidines which are useful as intermediates in the preparation of agents for the treatment of hepatitis C viral (HCV) infections.
2. Background Information
Substituted anisidines of the type described herein have been found to be useful as intermediates in the preparation of certain anti-HCV agents. See, e.g., U.S. Patent Application Publication Nos. US 2005/0020503 A1 and US 2005/0080005 A1, both herein incorporated by reference. However, there is a continuing need to develop an alternative practical and economical synthetic technique for the preparation of these substituted anisidines. The problem addressed by the present invention is to provide a practical and economical process which allows for the efficient manufacture of these compounds with a minimum number of steps.
Beringer, F. et al., J. Am. Chem. Soc., Vol. 75 (1953), 2635-2639; and Newman, M. et al, J. Org. Chem., Vol. 38, No. 23 (1973), 4073-4074, both describe processes for aromatization of certain cyclic oximes via acetate activation, but there is no disclosure or suggestion therein of the particular substituted oximes employed in the process of the present invention.